Time Range Overlap verification

time_range_overlap_validation.php

<?php 
/*
   @param String $time1 , Time representation
   @param String $time2 , Time representation
   @return boolean , wheter time range 1 and time range 2 overlaps or not
*/
 public function overlaps($from1,$to1,$from2,$to2)
 {
    $start1 = strtotime($from1);
    $end1 = strtotime($to1);

    $start2 = strtotime($from2);
    $end2 = strtotime($to2);

    return (($start1 < $end2) && ($start2 < $end1));
  }
?>